1. Field of the Invention
The present invention relates, generally, to automotive transmission systems and, more specifically, to a rotary shifter assembly for changing gears in a vehicle transmission.
2. Description of the Related Art
Conventional automotive powertrain systems known in the art include an engine in rotational communication with a transmission. The engine generates rotational torque which is selectively translated to the transmission which, in turn, translates rotational torque to one or more wheels. The transmission multiplies the rotational speed and torque generated by the engine through a series of predetermined gear sets, whereby changing between gear sets enables a vehicle to travel at different vehicle speeds for a given engine speed. Thus, the gear sets of the transmission are configured such that the engine can operate at particularly desirable rotational speeds so as to optimize performance and efficiency.
There are a number of different types of automotive transmissions known in the art. As such, changing between gear sets can be accomplished in a number of different ways, depending on the type of transmission. For example, so-called “manual” transmission systems typically include a clutch disposed between the engine and transmission for modulating engagement therebetween, and a shifter for changing between gear sets. The clutch and shifter are both mechanically connected to the manual transmission and are driver-actuated. In operation, the driver can manipulate the clutch and shifter to move the transmission between a freewheel “neutral” configuration, a “reverse” gear, and one or more forward gears, such as “first,” “second,” “third,” “forth,” etc. Thus, the driver determines when to change between gear sets and operates the shifter and clutch “manually”.
So-called “automatic” transmission systems, on the other hand, require substantially less driver input and use an electronic transmission controller that drives one or more solenoids to effect changing between forward gear sets. Solenoids are also used to modulate engagement between the engine and transmission. In conventional automatic transmission systems, modulation is achieved using a hydraulic torque converter. However, modern transmission systems may replace the torque converter with one or more electronically and/or hydraulically actuated clutches (sometimes referred to in the art as a “dual clutch” automatic transmission). In addition, conventional manual transmissions may be automated, whereby electronic actuators are used to shift between gear sets and modulate the clutch without relying on exclusively on operator interaction. Irrespective of how modulation is effected, automatic transmission systems rely on the transmission controller to determine when to change between forward gear sets. Thus, the transmission controller “automatically” modulates engagement between the engine and transmission and shifts between forward gear sets.
Despite the convenience afforded by automatic transmission systems in changing between forward gear sets, driver interaction is still required to select between different vehicle operating modes, such as “park,” “reverse,” “neutral,” “drive,” and/or “sport/manual.” To that end, the automatic transmission system also includes a shifter assembly in communication with the transmission and/or transmission controller.
Historically, shifter assemblies used with automatic transmissions were mechanically connected to the transmission via one or more linkages and/or cables. However, given the trend in the art of utilizing electronic actuators to control automatic transmission systems, modern shifter assemblies are increasingly designed as “drive-by-wire” so as to control the transmission electronically and without mechanical linkages and/or cables. By eliminating mechanical linkages and cables connected to the transmission, electronic shifter assemblies provide significant advantages with respect to packaging size, weight, orientation, and placement within the vehicle. Moreover, electronic shifter assemblies provide opportunities for controlling transmission systems with enhanced functionality and features.
While shifter assemblies known in the prior art have generally performed well for their intended purpose, there remains a need in the art for an improved electronic shifter assembly that strikes a substantial balance between packaging size, component cost, manufacturability, functionality, usability, and ergonomics.